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Publication numberUS4813756 A
Publication typeGrant
Application numberUS 07/148,071
Publication dateMar 21, 1989
Filing dateJan 25, 1988
Priority dateJan 25, 1988
Fee statusPaid
Publication number07148071, 148071, US 4813756 A, US 4813756A, US-A-4813756, US4813756 A, US4813756A
InventorsAnatoly Frenkel, Chinlon Lin
Original AssigneeBell Communications Research, Inc.
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Etalon filters for optical channel selection in wavelength division multiplexed fiber systems
US 4813756 A
Abstract
Filter arrangements (400,500,600) are disclosed for tunable channel selection in optical wavelength division multiplexed systems. Each filter arrangement has an etalon device (e.g. 401-403) as a simple, compact, in-line component which is rotatably adapted for interposing between the ends of fiber optic cables for interconnecting the cables. An optical beam emanating from a free end of each cable end is focused and directed to the etalon device by a collimated lensed connector (e.g. 411). Identical etalon devices may be stacked and ganged for rotation in unison to increase the number of system channels that may be propagated. Non-identical etalon devices may be stacked and made independently rotatable to increase the free spectral range of the system.
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Claims(12)
What is claimed is:
1. A device for interconnecting two optical fibers comprising
means, coupled to the fibers, for registering the free ends of the fibers and for collimating optical energy propagating over the fibers, and
mechanically rotatable etalon means, maintained in optical energy transfer relation with said registering and collimating means, for selectively transmitting optical energy between the fibers.
2. A device for linking first and second optical fibers comprising
first and second collimated beam connectors for receiving and registering the terminating ends of the first and second fibers, respectively, and
a mechanically rotatable etalon arrangement, interposed in optical energy transfer relationship between said connectors, for filtering optical energy transmitted by one of the fibers to the other one of the fibers.
3. The device recited in claim 2 wherein said mechanically rotatable etalon arrangement includes a single, solid core etalon filter and wherein said connectors and said filter are adapted to be substantially in-line with the fibers.
4. The device as recited in claim 2 wherein said mechanically rotatable etalon arrangement includes a cascade of etalon filters.
5. The device as recited in claim 4 wherein each of said etalon fibers is a solid core type etalon filter.
6. The device as recited in claim 2 wherein said mechanically rotatable etalon arrangement includes stacked, identical etalons ganged for rotation.
7. The device as recited in claim 2 wherein said mechanically rotatable etalon arrangement inludes stacked, non-identical etalons that are independently rotatable.
8. The device as recited in claim 2 wherein said arrangement is angle tunable.
9. An optical channel selection filter mounted for coupling two single mode optical fibers comprising
means for registering the free ends of the fibers and for focusing an optical signal present on the fibers into an optical beam, and
means, in energy transfer relation with said means for registering and focusing, for receiving and selectively filtering said beam, said means for receiving and filtering including a circular cross-section substrate having a coating deposited on the surfaces of said substrate, said surfaces formed substantially in parallel, said coating-substrate combination having predetermined transmsision and reflection characteristics, said means for receiving and filtering being mounted for mechanical rotation about an axis substantially transverse to said optical beam.
10. An optical channel selection filter mounted for coupling two single mode optical fibers comprising
means for registering the free ends of the fibers and for focusing an optical signal present on the fibers into an optical beam, and
means in energy transfer relation with said means for registering and focusing, for receiving and selectively filtering said beam, said means for receiving and filtering including a circular cross-section substrate having a coating deposited on the surfaces of said substrate, said surfaces formed substantially in parallel, said costing-substrate combination having predetermined transmission and reflection characteristics,
wherein said coating-substrate combination has a thickness of substantially ##EQU10## where n is the index of refraction of said combination, ##EQU11## with φmax being the maximum wavelngth component of said beam and FR being the free spectral range.
11. The filter as recited in claim 10 having a diameter substantially the same as the diameter of a cable housing the fibers for in-line insertion.
12. The filter as recited in claim 11 wherein said coating-substrate combination is rotatably mounted to effect tuning.
Description
FIELD OF THE INVENTION

This invention relates generally to an optical fiber communication system and, in particular, to in-line, angle-tuned etalon filter arrangements for optical channel selection in high-density wavelength division multiplexed (WDM) systems.

BACKGROUND OF THE INVENTION

In a typical optical WDM distribution system, a plurality of multiplexed signals are propagated over an optical medium to each receiver in the system and one of these signals is selected for detection within the receiver. The selection is often accomplished by interposing a wavelength sensitive optical filter between the medium and each receiver. In more specific terms, for instance, optical signals from each of N different optical signal generators with wavelengths of φ1, φ2, . . . , φN, respectively, are multiplexed and propagated over a system fiber connecting the various receivers. A given filter passes one of the wavelengths, say φi, from the composite set of wavelengths present on the fiber through to the associated receiver. For enhanced performance, the filter may be tunable so that a particular wavelength from the prescribed set may be optionally seleted. Such a tunable channel selection technique is important in order to increase the information capacity and system flexibility of short-haul communication systems such as in the local telephone loop wherein the number of multiplexed signals can range into the hundreds.

Conventional WDM filtering techniques have utilized dielectric-coated, optical interference filters or diffraction gratings. Interference filters usually have limited spectral resolution and are not tunable, thereby restricting their use to systems with a few number of channels. Diffraction gratings offer better spectral resolution, but because they are relatively bulky, lousy and expensive, they are not viable for in-line, short-haul applications.

Several, more recent alternatives have been proposed. Representative of these alternatives to tunable channel selection, for instance, is the article "Tunable Optical Multi/Demultiplexer for Optical FDM Transmission System", authored by Inoue et al and published in the Electronics Letters, vol. 21, pp. 387-389 (1985). As reported, a Mach-Zender interferometer is proposed as a tunable optical filter with very fine spectral resolution, but the so-called finesse is only on the order of 2 and this severely limits the number of channels that may be filtered. Moreover, the configuration is rather complex in that two directional couplers, a piezoelectric phase shifter, and polarization-holding fibers are required. Another article, entitled "Electro-Optically Tunable, Narrowband Ti:LiNbO3 Wavelength Filter", by Heismann et al as published in the Electronic Letters, vol. 23, pp. 572-574 (1987), reports on a tunable filter, but it has limitations in that high operating voltages are required and the tuning range is narrow.

Also, different types of Fabry-Perot interferometers have been proposed as a tunable filter for optical channel selection. Representative of these proposals are the following two articles: "WavelengthSelective Filters for Single-Mode Fiber WDM Systems Using Fabry-Perot Interferometers" authored by S. R. Mallinson and appearing in Applied Optics, 26, pp. 430-436 (1987); and "Pigtailed High-Finesse Tunable Fiber Fabry-Perot Interferometers with Large, Medium and Small Free Spectral Ranges" authored by J. Stone et al and appearing in Electronics Letters, Vol. 23, pp. 781,783 (1987). These techniques involve difficult alignment procedures to achieve high parallelism of interferometer surfaces. Furthermore, optical wavelength tuning requires very accurate linear movement (on the order of much less than one micron) usually using a piezoelectric element, and very high thermal stability, especially in a real field environment.

In general, the recent alternatives are deficient for tunable channel selection, short-haul applications because of one or more of the following limitations: require highly accurate adjustment and positioning; reflection of unselected signals may introduce source and system noise; cannot be utilized inline; limited spectral resolution; small finesse; high voltages required; difficult alignment and tunability mechanism; complexity; bulkiness; lousy; and expensive.

SUMMARY OF THE INVENTION

These and other shortcomings and limitations are obviated, in accordance with the present invention, by providing an angle-tuned etalon-based structure which is passive, simple and compact so it may be used for in-line applications.

In one embodiment of the present invention, a device for interconnecting two optical fibers includes: means for registering the free ends of the fibers and for collimating the optical beam emanating from the fiber ends; and a single etalon, rotatably adapted, for receiving the collimated energy and for selectively transmitting optical signal between the fibers.

Another embodiment includes replacing the single etalon with a multiplicity of identical etalons which may be stacked and ganged for rotation in unison. This arrangement increases the number of channels that may be propagated over the system. Still another embodiment utilizes numerous stacked but non-identical etalons in place of the single etalon. In this arrangement, the etalons are independently rotatable, thereby increasing the free spectral range of the system.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 depicts, in block diagram form, the optical communication system under consideration in accordance with the present invention;

FIG. 2 is a pictorial diagram of a single, inline, fiber-coupled etalon filter arrangement in accordance with the present invention;

FIG. 3 is a pictorial representation of a single etalon device depicting design angles and the thickness dimension;

FIG. 4 is a pictorial representation of an inline, fiber-coupled etalon arrangement wherein etalons are stacked as ganged, parallel identical etalons; and

FIG. 5 is a pictorial representation of an inline, fiber-coupled etalon filter arrangement wherein non-identical etalons are stacked but independently controllable.

DETAILED DESCRIPTION Overview

The general multiple transmitter-receiver system 100 under consideration is depicted in block diagram form in FIG. 1. In system 100, N transmitters 101,102, . . . , 103 are arranged to communicate with M receivers 301,302, . . . , 303 over interposed optical channel 110. In the embodiment depicted in FIG. 1, channel 110 is a star coupler which serves to buffer and multiplex the output signals of the various transmitters and propagate the multiplexed signals to the various receivers. An exemplary star coupler building block component is Model ACS 11 as provided by JDS Optics Inc. of Ottawa, Canada. Each transmitter 101, 102 or 103 generally transmits an optical signal at a wavelength designated as φi, i=1, 2, . . . , N, respectively. For instance, transmitter 101 propagates a signal having optical wavelength φ1. In one illustrative embodiment, the transmitters are distributed feedback (DFB) laser diodes operating in the 1550 nm region and channel 110 comprises any commercially available single-mode fiber supporting propagation in this region. In many applications, the wavelengths between adjacent signals are separated by a constant Δφ, that is, φi+1i =Δφ for i=1,2, . . . N-1.

Signals are delivered from main channel 110 via fiber paths 111,112, . . . , 113, which, in turn, feed etalon arrangements 201,201, . . . , 203, respectively. The composite signal on channel 110 due to all the propagating signals has been shown as (φ1, φ2, . . . , φN) as it appears on each of the individual paths. Each etalon arrangement has an output which serves as an input to an associated receiver. For instance, etalon 201 is coupled to receiver 302 via interposed fiber path 211. In one illustrative embodiment, each receiver 301, 302 or 303 is a direct detection type receiver well-known in the art.

In general, a transmitter having wavelength φi propagates its signal to one of the M receivers, so the function of the etalon arrangement associated with that particular receiver is to filter the wavelength φi from the composite signal on channel 110. For instance, in FIG. 1, receiver 301 is shown as detecting wavelength φi as provided by etalon arrangement 201 over path 211.

Single Etalon Embodiment

The basic building-block component for each etalon filter-arrangement 201,202, . . . , 203 in FIG. 1 is an angle-tuned etaon device. FIG. 2 is a pictorial diagram of an in-line, fiber-coupled filter arrangement 400 comprising angle-tuned etalon device 401 and collimated beam lensed connector pair 411 and 412 coupling single-mode fiber ends 421 and 422, respectively to etalon 401. Etalon 401 is arranged for rotational movement (counter-clockwise arrow) to accomplish wavelength selection simply by angle tuning. For example, etalon 401 may be mounted in a swivel type holder (not shown) that encompasses circularly shaped etalon 401. Moreover, connectors 411 and 412 are used for collimating and refocusing the fiber beam into etalon chamber 402. Such connectors are commercially available as Lamdak single-mode fiber connectors provided by the Kodak Corp.

To derive information about the design parameters and therefore the performance characteristics of etalon 401, reference is made FIG. 3. The so-called internal angle of incidence θ, which is related to the angle of rotation θ' (θ' is the acute angle between light beam 513 and line 514 normal to surfaces 511 and 512), corresponds to the optical channel signal with wavelength φi according to the relation ##EQU1## where m is an integer

n is the etalon index of refraction,

sinθ=sin θ'/n,

and L is the etalon thickness.

In equation (1), there are two unknowns, namely, m and L. To determine these values, the following procedure is used:

(i) A free spectral range (FR) is set equal to or greater than the system wavelength range where (φmaxmin), where φmax and φmin are the maximum and minimum wavelengths over which etalon 401 will be tuned. The value of m in equation (1) is determined from ##EQU2## where . represents the integer part operator. The value determined via equation (2) is rounded down to insure that the value of FR (FRmax /m) is such that FR ≦φmaxmin.

(ii) The thickness of the etalon is then given by ##EQU3##

Once the thickness L and integer m have been determined, the minimum spacing or signal separation may then be obtained once two other parameters, namely, the minimum transmission coefficient (Tmin) and the minimum acceptable level of crosstalk (K) are specified by the system designer. This separation is then given by ##EQU4## where F is the so-called finesse factor, ##EQU5## where Rmax is the maximum reflectivity of etalon plates 511 and 512, ##EQU6## and where A is the coating absorption coefficient for plates 511 and 512 as determined by the coating manufacturing process.

In deriving equations (4)-(6), it has been presumed that surfaces or plates 511 and 512 are parallel and that the diameter of the beam emanating from connector 411 or 412 is small.

The maximum number of optical signal channels detectable with etalon 401 for the given and derived parameters then becomes ##EQU7##

Typical design values for solid etalon 401 utilizing a coating deposition technique to produce plates 511 and 512 are:

______________________________________Givenφmin =          1510        nmφmax =          1560        nmTmin =    0.80K =            0.1n =            1.5A =            0.003ThenL =            16.1        micronFR =      50.3        nmm =            31Rmin =    0.97F =            103Δφmin =          1.4         nmand Nmax =          36,______________________________________

all for an operating region in the 1550 nm range. The diameter of each etalon plate 511 or 512 for an in-line application is typically no greater than 10 mm. Plates 511 and 512 are deposited on substrate 403, typically a silicon-type material. The tuning angle for tuning from one laser wavelength to the next ranges typically from 0.5 to 5 degrees depending on the optical channel spacing and angle θ.

Multiple Etalons

The number of optical channels which can be simultaneously used with a single etalon arrangement may still be somewhat limited for certain applications. Limitations occur because all optical channels are constrained to be within one free spectral range. Also, the spectral spacing between channels is restricted due to the conflicting requirements of high optical throughput (which restricts the maximum reflectivity of etalon surfaces), and the minimum acceptable crosstalk (which requires maximization of the reflectivity of etalon surfaces). Improvements in the crosstalk performance, a significant decrease in the minimum channel spacing and an increase in the number of multiplexed channels can be effected with the use of multiple etalons. Two cases are considered, namely, ganged, identical etalons and stacked, non-identical, independently controlled etalons.

The first case, as depicted by etalon arrangement 500 in FIG. 4, allows for a significant decrease in crosstalk and, therefore, decrease in the minimum optical channel spacing at the expense of increased transmission loss. The expression for the channel spacing is ##EQU8## where r is the number of identical etalons 501,502, . . . , 503 of FIG. 4. Moreover, if a single etalon has a maximum transmission T1, then the transmission TR becomes

TR =(T1)r.

This technique still requires that all the channels be placed within one free spectral range as with a single etalon.

The second case, as depicted by etalon arrangement 600 in FIG. 5, allows for the use of etalons to expand the range of optical signals beyond the free spectral range of each individual etalon, that is, the composite free spectral range of the stacked, non-identical and independently controlled etalons is much greater than that of a single etalon. As depicted in FIG. 5, each etalon is arranged to be individually rotated for separate tuning. The design of such a stacked arrangement is complex and generally requires computer simulation and optimization. However, as an aid to the types of considerations that must be addressed in the design process, certain design criteria for two stacked but independently tunable etalons are presented.

First, the free spectral range of the etalons should not be a multiple of each other. This constraint results in the etalon thickness being expressed as: ##EQU9## m1 ≠2m2 ≠2m1.

Secondly, crosstalk may be reduced by choosing the optical channel spacing to be non-multiple to the free spectral ranges of both etalons.

Also, as in the above case, the increase of multiplexed capacity is achieved at the expense of a reduction in the optical throughput. Generally, the transmission parameters of the individual etalons should be multiplied to obtain the overall transmission loss presented by etalon arrangement 600.

It is to be understood that the above-described embodiments are simply illustrative of the application of the principles in accordance with the present invention. Other embodiments may be readily devised by those skilled in the art which may embody the principles in spirit and scope.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3902130 *May 14, 1973Aug 26, 1975Jersey Nuclear Avco IsotopesImproved apparatus for lengthening laser output pulse duration
US4671604 *Feb 6, 1985Jun 9, 1987The United States Of America As Represented By The Secretary Of The Air ForceWavelength dependent, tunable, optical time delay system for electrical signals
Non-Patent Citations
Reference
1"A Conceptional Design on Optical Frequency-Division-Multiplexing Distribution Systems with Optical Tunable Filters", Hiromu Toba, Kyo Inque & Kiyoshi Nosu, IEEE Journal on Selected Areas in Communications, vol. SAC-4, No. 9, Dec. 1986.
2"Crosstalk Limits of Fabry-Perot Demultiplexers", S. R. Mallinson, Electronic Letters, Aug. 15, 1985, vol. 21, No. 17.
3"Electro-Optically Tunable, Narrowband Ti:LiNbO3 Wavelength Filter", F. Heismann, L. L. Buhl, R. C. Alferness, Electronic Letters, May 21, 1987, vol. 23, No. 11.
4"Optical FDM Transmission Technique", Kiyoshi Nosu, Hiromu Toba, and Katsushi Iwashita, Journal of Lightwave Technology, vol. LT-5, No. 9, Sep. 1987.
5"Pigtailed High-Finesse Tunable Fibre Fabry-Perot Interferometers with Large, Medium and Small Free Spectral Ranges", R. Glavina, S. Cucchi, G. L. Sicuranza, Electronics Letters, Jul. 16, 1987, vol. 23, No. 15.
6"Tunable Optical Multi/Demultiplexer for Optical FDM Transmission System", K. Inque, H. Toba & K. Nosu, Electronics Letters, Apr. 25, 1985, vol. 21, No. 9.
7"Ultrahigh Finesse Fiber Fabry-Perot Interferometers", J. Stone and D. Marcuse, Journal of Lightwave Technology, vol. LT-4, No. 4, Apr. 1986.
8"Wavelength-Selective Filters for Single-Mode Fiber WDM Systems Using Fabry-Perot Interferometers", Stephen R. Mallinson, Applied Optics, vol. 26, No. 3, Feb. 1, 1987.
9 *A Conceptional Design on Optical Frequency Division Multiplexing Distribution Systems with Optical Tunable Filters , Hiromu Toba, Kyo Inque & Kiyoshi Nosu, IEEE Journal on Selected Areas in Communications, vol. SAC 4, No. 9, Dec. 1986.
10 *Crosstalk Limits of Fabry Perot Demultiplexers , S. R. Mallinson, Electronic Letters, Aug. 15, 1985, vol. 21, No. 17.
11 *Electro Optically Tunable, Narrowband Ti:LiNbO 3 Wavelength Filter , F. Heismann, L. L. Buhl, R. C. Alferness, Electronic Letters, May 21, 1987, vol. 23, No. 11.
12 *Optical FDM Transmission Technique , Kiyoshi Nosu, Hiromu Toba, and Katsushi Iwashita, Journal of Lightwave Technology, vol. LT 5, No. 9, Sep. 1987.
13 *Pigtailed High Finesse Tunable Fibre Fabry Perot Interferometers with Large, Medium and Small Free Spectral Ranges , R. Glavina, S. Cucchi, G. L. Sicuranza, Electronics Letters, Jul. 16, 1987, vol. 23, No. 15.
14 *Tunable Optical Multi/Demultiplexer for Optical FDM Transmission System , K. Inque, H. Toba & K. Nosu, Electronics Letters, Apr. 25, 1985, vol. 21, No. 9.
15 *Ultrahigh Finesse Fiber Fabry Perot Interferometers , J. Stone and D. Marcuse, Journal of Lightwave Technology, vol. LT 4, No. 4, Apr. 1986.
16 *Wavelength Selective Filters for Single Mode Fiber WDM Systems Using Fabry Perot Interferometers , Stephen R. Mallinson, Applied Optics, vol. 26, No. 3, Feb. 1, 1987.
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4867520 *Aug 28, 1984Sep 19, 1989Licentia Patent Verwaltungs GmbhOptical fiber multiplexer
US5050954 *Jan 12, 1990Sep 24, 1991At&T Bell LaboratoriesMultiport optical devices
US5177354 *Dec 10, 1990Jan 5, 1993Nippon Telegraph And Telephone CorporationDevice and a method for distinguishing faults employed in an optical transmission system
US5202782 *Jan 14, 1991Apr 13, 1993Canon Kabushiki KaishaOptical communication method and optical communication system
US5212745 *Dec 2, 1991May 18, 1993Micron Optics, Inc.Fixed and temperature tuned fiber fabry-perot filters
US5212746 *Jan 15, 1992May 18, 1993Micron Optics, Inc.Single wafered ferrule fiber fabry-perot filters
US5283845 *Jul 20, 1992Feb 1, 1994Jds Fitel Inc.Multi-port tunable fiber-optic filter
US5287214 *Apr 8, 1992Feb 15, 1994Northern Telecom LimitedFabry-Perot optical filters
US5289552 *Aug 12, 1992Feb 22, 1994Micron Optics, Inc.Temperature compensated fiber fabry-perot filters
US5361155 *Mar 23, 1993Nov 1, 1994Alcatel CitOptical filter tuned by rotation and comprising a Fabry-Perot interferometer
US5375181 *Oct 13, 1993Dec 20, 1994Micron Optics, Inc.Temperature compensated fiber fabry-perot filters
US5416629 *Dec 2, 1992May 16, 1995General Instrument CorporationIntensity modulated digital optical communications using a frequency modulated signal laser
US5422970 *Dec 3, 1993Jun 6, 1995Micron-Optics, Inc.Temperature compensated fiber Fabry-Perot filters
US5479547 *Oct 13, 1994Dec 26, 1995Fujitsu LimitedOptical multiplexer and demultiplexer module including multiplexing and demultiplexing filter film
US5491582 *Apr 14, 1994Feb 13, 1996Nec CorporationLight-receiving module
US5504608 *May 25, 1995Apr 2, 1996At&T Corp.Adjustable filter for tuning multimode optical signals
US5646762 *Nov 7, 1995Jul 8, 1997Lucent Technologies Inc.Optical communication system using tandem Fabry-Perot etalon for wavelength selection
US5781341 *Jan 24, 1996Jul 14, 1998Dicon Fiberoptics, Inc.For filtering an incident light beam
US6075647 *Jan 30, 1998Jun 13, 2000Hewlett-Packard CompanyOptical spectrum analyzer having tunable interference filter
US6125220 *Mar 25, 1999Sep 26, 2000Copner; NigelInterferometric optical device including a resonant optical cavity
US6168319Aug 5, 1999Jan 2, 2001Corning IncorporatedSystem and method for aligning optical fiber collimators
US6204970Dec 13, 1999Mar 20, 2001Corning IncorporatedMethod of spectrally tuning a filter
US6215592Mar 19, 1999Apr 10, 2001Ciena CorporationFabry-perot optical filter and method of making the same
US6269203May 21, 1999Jul 31, 2001Radiant PhotonicsHolographic optical devices for transmission of optical signals
US6276806Aug 24, 1999Aug 21, 2001Lionel John SkillicornMicro-etalon and associated methods
US6282337Sep 24, 1999Aug 28, 2001Radiant Photonics, Inc.System and method for wavelength division multiplexing and demultiplexing
US6341040 *Jun 8, 1999Jan 22, 2002Jds Uniphase CorporationMulti-plate comb filter and applications therefor
US6349103Dec 28, 1999Feb 19, 2002Samsung Electronics Co., Ltd.Cold-start wavelength-division-multiplexed optical transmission system
US6362904Nov 20, 2000Mar 26, 2002Robert H. CormackTunable optical filter with retained complementary output
US6384978 *Mar 19, 1999May 7, 2002Qtera CorporationTemperature-compensated optical filter assemblies and related methods
US6459844Jul 13, 1999Oct 1, 2002Jds Uniphase CorporationTunable fiber optic filter
US6469847 *Aug 22, 2000Oct 22, 2002Jds Uniphase Corp.Temperature compensated optical filter
US6470117Dec 4, 1998Oct 22, 2002Radiant Photonics, Inc.Compression-molded three-dimensional tapered universal waveguide couplers
US6483967Jun 27, 2001Nov 19, 2002Finisar CorporationOptical waveguide coupler for interconnection of electro-optical devices
US6539145Oct 30, 2000Mar 25, 2003Infineon Technologies AgModule for multiplexing and/or demultiplexing optical signals
US6563616Feb 21, 1999May 13, 2003Electro-Optical Sciences, Inc.Optical demultiplexer
US6567432 *Jan 14, 2000May 20, 2003Electronics And Telecommunications Research InstituteWideband multichannel fiber lasers with output power equalization
US6587608Apr 27, 2001Jul 1, 2003Chameleon Optics, Inc.Reconfigurable, all optical add/drop nodes using non-interrupting switching apparatus and methods
US6600604 *Dec 4, 2000Jul 29, 2003Ciena CorporationAthermal thin film filter
US6608685May 14, 2001Aug 19, 2003Ilx Lightwave CorporationTunable Fabry-Perot interferometer, and associated methods
US6631019Jul 5, 2000Oct 7, 2003Sri InternationalReconfigurable multichannel transmitter for dense wavelength division multiplexing (DWDM) optical communication
US6707609Mar 23, 2001Mar 16, 2004Optical Coating Laboratory, Inc.Extrinsically athermalized optical filter devices
US6721468Jun 7, 2002Apr 13, 2004Ilx Lightwave CorporationResonantly driven fiber polarization scrambler
US6724789Dec 13, 2001Apr 20, 2004Sri InternationalDense wavelength division multiplexing (DWDM) fiberoptic source
US6781757Apr 19, 2002Aug 24, 2004Micron Optics, Inc.Polarization insensitive tunable optical filters
US6795654Sep 18, 2001Sep 21, 2004Robert H. CormackTunable add/drop filter
US6804063Oct 25, 2002Oct 12, 2004Research Electro-Optics, Inc.Optical interference filter having parallel phase control elements
US6844946Mar 29, 2001Jan 18, 2005California Institute Of TechnologyTunable holographic filter
US6885782Jun 25, 2002Apr 26, 2005Ilx Lightwave CorporationFeedback polarization controller
US6904206Oct 15, 2003Jun 7, 2005Micron Optics, Inc.Waferless fiber Fabry-Perot filters
US6947218Aug 30, 2002Sep 20, 2005Research Electro-Optics, Inc.Fabry-perot etalon with independently selectable resonance frequency and free spectral range
US6947220Nov 21, 2000Sep 20, 2005Ksm Associates, Inc.Devices for information processing in optical communications
US7023620Jul 1, 2004Apr 4, 2006Research Electro-Optics, Inc.Beam array pitch controller
US7063466Dec 18, 2003Jun 20, 2006Micron Optics, Inc.Selectable and tunable ferrule holder for a fiber Fabry-Perot filter
DE10054372A1 *Oct 30, 2000May 29, 2002Infineon Technologies AgUnit for multiplexing and/or demultiplexing optical signals, has at least one wavelength selective filter that is adjustable in terms of angle of incidence of light beams
DE10054372B4 *Oct 30, 2000Oct 31, 2007Infineon Technologies AgBaugruppe zum Multiplexen und/oder Demultiplexen optischer Signale
EP0432734A2 *Dec 11, 1990Jun 19, 1991Nippon Telegraph And Telephone CorporationA device and a method for distinguishing faults employed in an optical transmission system
EP0530025A2 *Aug 27, 1992Mar 3, 1993Nec CorporationLight receiving module
EP0562953A1 *Mar 23, 1993Sep 29, 1993Alcatel CitOptical filter containing a Fabry-Perot interferometer tunable by rotation
EP0773640A2 *Oct 29, 1996May 14, 1997AT&T Corp.Optical communication system using tandem Fabry-Perot etalon for wavelength selection
WO2000026712A1 *Oct 29, 1999May 11, 2000E Tek Dynamics IncTunable fiber optic filter
WO2001011403A1 *Jul 10, 2000Feb 15, 2001Corning IncSystem and method for aligning optical fiber collimators
WO2001075494A2 *Feb 6, 2001Oct 11, 2001Corning IncOptical filtering device and method of making the same
WO2002008805A2 *Jul 10, 2001Jan 31, 2002George M MurrayFiber optic coupler with in-line optical component
Classifications
U.S. Classification385/73, 398/82
International ClassificationG02B6/34
Cooperative ClassificationG02B6/29358, G02B6/29395
European ClassificationG02B6/293I10, G02B6/293W10
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Effective date: 19990316
Owner name: TELCORDIA TECHNOLOGIES, INC. ROOM 1G112R 445 SOUTH
Jun 24, 1996FPAYFee payment
Year of fee payment: 8
Oct 6, 1992CCCertificate of correction
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Jan 25, 1988ASAssignment
Owner name: BELL COMMUNICATIONS RESEARCH, 290 WEST MOUNT PLEAS
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Effective date: 19880121
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Owner name: BELL COMMUNICATIONS RESEARCH, A CORP. OF DE, NEW J